Some things and/or people in our lives are not going to change. So there's no point in getting our kilts in a wad over them, or reciting a perpetual litany of grievances against them - which others tire of hearing. In fact, sometimes it's the nemesis that presents himself or herself which may mirror the impending downfall of things inside ourself that need to go - a reflection of what we might want to ignore, calling for deeper repentance - requiring the absolute surrender of self to the Lord.
This is why introspection needs to be part of our prayer life on a consistent basis. We may want to ask, Lord, why is this person continually presenting himself or herself in ways that set me on edge? Why does he or she not change or do what I think they really should? What is this all about anyway? When this happens over and over, it's time to look inside with the brilliant searchlight of the Holy Spirit, in deeper ways than ever before. What is it inside of me that needs to go that this person or situation is reflecting, that I cannot seem to be free of it? As James admonishes, if anyone needs wisdom, let him ask of God, but let him do so without doubting.
Also recommended is a serious reading and consideration of the book of Job - some of the most ancient wisdom out there. Sometimes things may not be as simplistic as our finite minds make them out to be, especially when the “nemesis” presents itself as the complete dismantling of everything that was status quo up to that point.
If you come away from reading this thinking it applies to your nemesis and not to you, then all that can be said is, Whoever hath ears to hear, let him hear.
Or as we might say it these days, if the shoe fits, wear it.